This application relates generally to airfoil inspection and particularly to airflow inspection processes applied to turbine blades and vanes.
All turbines airfoils, both blades and vanes, must be inspected to ensure proper airflow through the airfoil. This is done through manual airflow inspection processes using pressure tappers. Each airfoil has specific pressure tap requirements that must be met during inspection. Pressure taps are used to measure the amount of air at a particular hole in an airfoil during inspection. Pressure taps work by aligning with a particular hole being tested and running air through the passages associated with that hole. The pressure tapper can then detect the airflow through the hole and associated passages, including the pressure of the airflow.
Pressure taps have been difficult to automate due to variations in airfoil casting, grind classes, and hole drill true positions, particularly in turbine vanes. Thus, current airflow inspection processes are dependent on human operators. The operator uses a pen-like probe to locate and cover the correct hole prior to pressure tapping the hole. The alignment and inspection process is time consuming and risk injuries to operators. Additionally, the process is difficult to normalize from operator to operator.